Method of making curb separators

ABSTRACT

A cutting die is used to simultaneously form two curb spacers of L-shaped form including a vertical curb flange and a horizontal apron flange. The cutting rule is confirmed within a rectangular area. The cutting rule defining the upper surfaces of one horizontal flange forms the upper surface of a similar spacer in inverted relation to the first, and the ends of the cutting rule define the vertical flanges of both separators. The opposite sides of the die are unconfined so that when a rectangular blank is cut on the die, the two separators may move apart, the opposite longitudinal edges of the die forming the bottom surfaces of the spacers.

United States Patent Inventor St. Paul, Appl. No. 848,217 Filed Patented Assignee Oct. 12,

Roger L.

Ling'ofelt Minn.

Aug. 7, 1969 North Central Supply Company Ramsey County, Minn.

METHOD OF MAKING CURB SEPARATORS 5 Claims, 3 Drawing US. Cl

Int. Cl

Field of Search Primary Examiner-James M. Meister Attorney-Robert M. Dunning ABSTRACT: A cutting die is used to simultaneously form two curb spacers of L-shaped form including a vertical curb flange and a horizontal apron flange. The cutting rule is confirmed within a rectangular area. The cutting rule defining the upper surfaces of one horizontal flange forms the upper surface of a similar spacer in inverted relation to the first, and the ends of the cutting rule define the vertical flanges of both separators. The opposite sides of the die are unconfined so that when a rectangular blank is cut on the die, the two separators may move apart, the opposite longitudinal edges of the die forming the bottom surfaces of the spacers.

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METHOD OF MAKING CURB SEPARATORS This invention relates to an improvement in method of making curb separators, and deals particularly with a method of cutting tar or asphalt-impregnated sheet so that it will not stick in the dies.

Curb separators are used at intervals throughout the length of a concrete curbing so as to permit a certain degree of expansion between the sections. The material used is a fibrous felt material which is impregnated with tarry material such as an emulsion of tar or asphalt so as to be resistant to the elements. These separators are normally substantially L-shaped in form and include a vertically extending portion which forms the actual curb, and the horizontal apron section which extends toward the center of the road from the curb and actually forms the marginal edge portion of the roadway. In most instances, before having a road, the curbs are formed in opposite parallel relation, and the paving is later filled in between the horizontally extending aprons of the curbing. In order that the curbing may be formed to a suitable shape, the separators are nonnally the same cross-sectional shape as the curbing are inserted at prescribed intervals.

The sheet material which formed the separators may be perhaps one-half inch in thickness and is somewhat yieldable to pennit the necessary expansion of the concrete. For a considerable time, attempts have been made to die-cut these separators from rectangular blanks of material. The cross-sectional shape of the curbing is such that the vertically extending curb portions thereof are normally approximately one-half of the thickness of the laterally extending apron flanges thereof. With this arrangement, two oppositely arranged separators may be formed of a rectangular blank of proper size. However, insofar as I can determine, such separators have never been successfully formed in a cutting press of conventional form. The cutting die which cuts these separators to the proper shape are normally formed of diecutting rule which is bent to the proper shape to cut out the periphery of the separator. However, due to the thickness of the material being cut, and due to the nature of the material used for such purposes, when the material is forced into the die, the separator is slightly compressed due to the fact that the cutting rule entirely encircles the separator, and due also to the fact that cutting rule must be thick enough to keep from flexing when the blank is forced into the die, and the sharpened edge of the cutting rule is normally on a plant intermediate the planes of the parallel surfaces of the rule. Where the material being cut is flexible, such as paperboard, the die-cut part or parts may be disengaged from the cutting rule by merely providing resilient blocks of rubberlike material along these marginal edges of the die-cut piece and which are secured to the base of the die. However, when the material being die-cut is as thick as is necessary for separators, and is impregnated with a tar or tarlike material, such as asphalt, the die cut piece or pieces wedge the die and become damaged if an attempt is made to remove them. As a result, it has been common practice to form the separators by cutting each separator about its periphery with a band saw. Such a process inevitable leads to inaccuracies and variations in shape, as even a skilled bandsaw operator will not make all of the separators exactly similar in shape. Furthermore, individually sawing out the separators is a slow and tedious task, as well as a costly operation.

I have found that separators be formed through the use of a hydraulic press or the like through the use of a cutting die which eliminates the tendency for the separators to wedge in the die. This is accomplished by using a blank of material which is of a width substantially equal to twice the depth of a horizontally extending flange of the curbing. A die is formed which includes a cutting rule shaped to the contour of the entire upper portion of the separator, but which eliminates the cutting rule usually used to define the lower surface of the separator. The curbing normally tapers, the vertical flange being narrowest at its upper extremity. As a result, the blank is not confined as the cutting rule forming the lower edge of the blank is omitted from the die. When the blank is accurately placed upon the die, and the hydraulic press is closed, two separators are simultaneously formed which are of identical shape and size, and which may be readily removed when the press is opened. As a matter of fact, when the press is completely closed, the parts of the blank are normally forced away from the cutting rule so that the two separators may be readily lifted out, and the scrap may be discarded.

These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claims. In the drawings forming a part of the specification: 7

FIG. 1 is a diagrammatic view of a blank, showing a pair overlapping separators formed therefrom.

FIG. 2 is a diagrammatic view of the cutting die used to form the separators shown in H6. 1.

FIG. 3 is a view similar to FIG. 2, but showing the manner in which the separators tend to move apart at the completion of the diecutting operation.

The letter A indicates in broken outline the rectangular blank from which two curb separators B are to be formed. Preferably, the length of the blank A is equal to the length of the two overlapped separators, while the width of the blank or the vertical dimensions as shown in FIG. I, is twice the height of the horizontal apron flanges of the separators B.

As is indicated, the separators include vertical flanges l0, and horizontal flanges 11, the flanges being arranged in an L- shaped formation. THe outer edge 12 of the vertical flange 10 is at a slight angle from the vertical, the edge 12 sloping inwardly somewhat from bottom to top. The upper edge 13 of the separator is connected to the angled edge 12 along a relatively small radius curve 14. The top portion 13 slopes slightly inwardly and downwardly from the rounded comer 14. The top surface 13 is connected along a reversely curved or S- shaped curve 15 to the upper surface 16 of the horizontal flange 11. The inner end 17 'of the horizontal flange 11 is at an angle to the vertical which is slightly less than the angled the well surface 12. The lower edges 19 of the separator extend along the edges of the blank A, and the upper surfaces 16 are midway between the edges 19.

The letter C indicates the cutting die from which the separators B are formed. The cutting rule forming the major portion of the die may either be a single length of rule or may be a plurality of lengths in end-abutting relation to form the continuous cutting edge. The die C includes a base 20 in which the cutting rule is mounted. As indicated, the cutting rule being bent as indicated at 22 to form the rounded separator corners 14, and portions 23 designed to form the upper edges 13 of the separators. The cutting rule is then formed into reversely curved portions 24 and 25 which are connected by a straight section of rule 26 which is designed to form the upper surfaces 16 of the horizontal flanges of the separators.

The end edges 17 of the horizontal flanges 11 are formed by straight lengths of cutting rule 27 which are almost parallel to the end portions 21, but which slope apart at a sufficient angle so that the ends of the separators will not become wedged between the rule portions 21 and 27.

It will be noted that with this arrangement, the sheet material from which the board is formed is not encircled in any area, and both the separators themselves and the scrap material is free to become disengaged from the cutting rule. As a matter of fact, as the cutting operation is completed, the separators B normally tend to spring apart to some extent in the manner indicated in FIG. 3 of the drawings. As a result, when the press is opened, the separators may be removed, and the scrap may be removed and discarded, to prepare for a new cycle of operation.

The sheet material from which the separators are formed is a thick fibrous substance heavily impregnated with asphalt, tar or similar material which is unaffected by moisture. While this material cannot normally be cut in a cutting die of conventional form, it may be quickly and easily cut in the die disclosed in FIG. 2 in view of the fact that the separators and the scrap material cannot be wedged in any part of the die.

In accordance with the patent statutes. 1 have described the principles of construction and operation of my improvement in method of making curb separators, and while 1 have endeavored to set forth the best embodiment thereof, I desire to have it understood that changes may be made within the scope of the following claims without departing from the spirit of my invention.

1. A method of producing curb separations from thick sheets of fibrous material, the separators being generally L- shaped in section including a vertical curb flange and a generally horizontal apron flange, the method including the steps of:

providing an elongated rectangular blank of the sheet material which is twice the height of the horizontal curb flange and at least the height of the vertical curb flange,

providing a die with cutting rule projecting therefrom, the rule defining the upper exposed surfaces of both flanges of two curb spacers arranged with the center portion of the cutting rule defining the upper surfaces of the horizontal flanges of two overlapping separators and the ends of the cutting rule defining the vertical flanges of the separators, one of which is inverted relative to the other,

placing the blank upon the die with the central portion of the cutting rule midway between and parallel to the longitudinal edges of the blank, and

applying pressure to cut the blank, the die forcing the separators outwardly.

2. The method of claim 1 and in which the vertical flange, as

well as the ends of the horizontal flange, increase somewhat in thickness toward the lower edges of the spacers.

3. The method of claim 1 and including the step of removing the pressure and removing the curb spacers from the die.

4. A die for use in forming curb spacers from thick sheets of impregnated fibrous material the curb spacers having a generally vertical curb flange, and a generally horizontal apron flange thereon forming an L-shaped structure having a flat bottom surface, the die including:

a base,

cutting rule projecting from said base and shaped to define the vertical curb flange of one spacer and the upper surface of the horizontal flange thereof, the portion of cutting rule defining the upper surface of the horizontal flange also defining the upper surface of a second spacer in inverted overlapping relation with the first, the cutting rule continuing to define the curb flange of the second spacer,

the area of said base on opposite sides of said cutting rule being free of obstruction to the separation of said spacers when separated by said cutting rule.

5. The structure of claim 4 and including a strip of cutting rule on each side of said first-named cutting rule defining the end edges of the horizontal flanges of the spacers, the areas on both sides of said stn'p being divergent from adjoining areas of said first-named cutting rule. 

1. A method of producing curb separations from thick sheets of fibrous material, the separators being generally L-shaped in section including a vertical curb flange and a generally horizontal apron flange, the method including the steps of: providing an elongated rectangular blank of the sheet material which is twice the height of the horizontal curb flange and at least the height of the vertical curb flange, providing a die with cutting rule projecting therefrom, the rule defining the upper exposed surfaces of both flanges of two curb spacers arranged with the center portion of the cutting rule defining the upper surfaces of the horizontal flanges of two overlapping separators and the ends of the cutting rule defining the vertical flanges of the separators, one of which is inverted relative to the other, placing the blank upon the die with the central portion of the cutting rule midway between and parallel to the longitudinal edges of the blank, and applying pressure to cut the blank, the die forcing the separators outwardly.
 2. The method of claim 1 and in which the vertical flange, as well as the ends of the horizontal flange, increase somewhat in thickness toward the lower edges of the spacers.
 3. The method of claim 1 and including the step of removing the pressure and removing the curb spacers from the die.
 4. A die for use in forming curb spacers from thick sheets of impregnated fibrous material the curb spacers having a generally vertical curb flange, and a generally horizontal apron flange thereon forming an L-shaped structure having a flat bottom surface, the die including: a base, cutting rule projecting from said base and shaped to define the vertical curb flange of one spacer and the upper surface of the horizontal flange thereof, the portion of cutting rule defining the upper surface of the horizontal flange also defining the upper surface of a second spacer in inverted ovErlapping relation with the first, the cutting rule continuing to define the curb flange of the second spacer, the area of said base on opposite sides of said cutting rule being free of obstruction to the separation of said spacers when separated by said cutting rule.
 5. The structure of claim 4 and including a strip of cutting rule on each side of said first-named cutting rule defining the end edges of the horizontal flanges of the spacers, the areas on both sides of said strip being divergent from adjoining areas of said first-named cutting rule. 